Analog and digital are two different animals.
All the TV's I've seen will only send out, via digital optical, only what it generates from it's own internal ATSC tuner. I can't recall one that will "pass thru" a digital signal from another device.
As for analog audio sources, (red/white phono plugs), it's not uncommon for a TV to pass these through to a receiver via their analog outputs.
hope this helps...